Arminidae Family

Family Arminidae

Most arminids have an elongate body that is soft and flattened. The mantle is usually large, broad, and thick often with strong longitudinal ridges on the upper surface although these may be replaced by irregular pustules or papillae, or even be absent. There are no cerata on the dorsum. The mantle and foot are approximately the same width, being widest anteriorly and tapering gradually to a rounded or pointed tail. In the genus Armina the mantle is attached posteriorly to the foot. Numerous glands or cnidosacs can be present along the mantle margin. Arminids have an oral veil that is distinct in appearance with short tentacular lobes laterally. Just in front of the rhinophores some species possess a transverse ridge or flap called a caruncle believed to be sensory in function. The rhinophores are distinctive – possessing a club with compact vertical lamellae and are located quite anteriorly and close together. They are retractile. Gills are present in the genus Armina but not in the genus Dermatobranchus. In Armina they are located anteriorly down the sides under the mantle brim and are leaf-like in structure whilst medially and posteriorly is a system of intricate lamellate outgrowths performing the same function. Arminids feed upon soft corals or sea pens.